ABSTRACT
Repeated serological testing tells about the change in the overall infection in a community. This study aimed to evaluate changes in antibody prevalence and kinetics in a closed cohort over six months in different sub-populations in India. The study included 10,000 participants from rural and urban areas in five states and measured SARS-CoV-2 antibodies in serum in three follow-up rounds. The overall seroprevalence increased from 73.9% in round one to 90.7% in round two and 92.9% in round three. Among seropositive rural participants in round one, 98.2% remained positive in round two, and this percentage remained stable in urban and tribal areas in round three. The results showed high antibody prevalence that increased over time and was not different based on area, age group, or sex. Vaccinated individuals had higher antibody prevalence, and nearly all participants had antibody positivity for up to six months.
ABSTRACT
Background Despite the success of adult vaccination against COVID-19, providing vaccines to children remains a challenge for policymakers globally. As parents are primary decision-makers for their children, we aimed to assess parents perceptions and intentions regarding COVID-19 vaccination in India. Methods A cross-sectional web-based study was designed, parents or caregivers (N=770) were recruited through snowball sampling using Google form. Cross-tabulation was performed by parents intention to vaccinate their children against COVID-19 virus with sociodemographic characteristics and their risk perception towards COVID-19, trust in the healthcare system, and their history of vaccine hesitancy behavior. Multivariable logistic regression analysis was performed to compute the predictors of child vaccination intention among Indian parents. Results Seven hundred seventy parents across the country have completed the survey. Of the 770 participants, 258 (33.5%) have shown intent to vaccinate their children. The stated likelihood of child vaccination was greater among parents who had a bachelors degree or higher education (aOR: 1.98, 95% CI: 1.15-3.51); as well as among parents who intended to vaccinate themselves (aOR: 2.35, 95% CI: 1.30-4.67). Parental concerns centered around vaccine safety and side effects. Conclusion Indian parents reported high knowledge of the COVID-19 virus and were aware of the development of a novel vaccine. However, about one-third of parents intended to vaccinate their children, and about half of them were not sure whether to vaccinate their children or not against the COVID-19 virus. The study highlighted the need for health promotion strategies that promote vaccine uptake among parents.
Subject(s)
COVID-19ABSTRACT
IntroductionThis study was aimed at assessing the vaccine effectiveness (VE) of Covishield, which is identical to the AstraZeneca vaccine, in preventing laboratory-confirmed Covid-19. MethodsUsing a test-negative case-control design, information on vaccination status of cases with Covid-19 among healthcare workers in our institution in Puducherry, India, and an equal number of matched controls, i.e., positive and negative for SARS-CoV-2 by RT-PCR, was obtained. The cases and controls were matched for age ({+/-}3 years) and date of testing ({+/-}3 days). The groups were compared using multivariable conditional logistic regression to calculate odds ratios (OR), with adjustment for gender, occupational role, presence of symptoms and presence of a comorbidity condition. Per cent vaccine effectiveness (VE) was calculated as 100 x (1-adjusted odds ratio). ResultsUsing data from 360 case-control pairs, VE of one dose and of two doses, in providing protection against Covid-19 was 49% (95% CI: 17%-68%) and 54% (27%-71%), respectively. In view of a difference in the proportion of cases and controls who had symptoms, a separate analysis of data from 203 pairs where both the case and the control had symptoms was done, which showed VE of 58% (28%-75%) and 64% (38%-78%) after one dose and two doses, respectively. Among cases with moderately severe disease that required oxygen therapy, VE following any number of vaccine doses was 95% (44%-100%). ConclusionCovishield vaccine protected significantly against Covid-19, with the protection after two doses being slightly higher than after one dose, and a particularly high protection rate against severe forms of disease.